Nurikabe @ Daily Sudoku

After Sudoku? Nurikabe!

The Nurikabe Book

The Nurikabe puzzles are not currently being updated. Visit the
archive for over 80 previously published
puzzles. You might also want to check
out the
Nurikabe Book.

Welcome to Nurikabe @ the Daily Sudoku!

Are you a Sudoku fan? Are you looking for a new challenge? Give
Nurikabe a try!

The latest puzzle is shown on the right. Three new puzzles are
available each week, on Mondays, Wednesdays and Fridays. Check
the puzzles page for
previous puzzles.

Like Sudoku, Nurikabe is played on a grid. Like Sudoku, Nurikabe
is a purely logic puzzle. Like Sudoku, each puzzle has only one
solution, and like Sudoku, that solution can be reached without
resorting to trial and error. Like Sudoku, puzzles can be very
easy, presenting even the beginner with a 5 or 10 minute diversion,
or very hard, occupying the hardened puzzler with a significant
challenge.

The Objective

The object of Nurikabe is to shade each square black or leave it
white, based on a few simple rules. Nurikabe does have more rules
than Sudoku, but they quickly become intuitive.

The rules

Each square must be black or white. Nurikabe has 4 additional rules:

Each group of white cells ("islands") must contain only one number

The number of white squares in a group must equal that number

All black squares must be linked together to form a continous
block (the "wall" or "stream")

Background

Like Sudoku, Nurikabe has its roots in Japan. In Japanese
folklore, the Nurikabe is an invisible wall that blocks the path of a
traveller. The Nurikabe puzzle is also known as "islands in the
stream". We mix "wall" and "island" metaphors mercilessly here!

Want more?

"The Nurikabe Book", by Sam Griffiths-Jones and published by
Harriman House, is now available from all good bookshops.